JPS615033A - Preparation of trifluoromethyl benzal chloride or derivative thereof - Google Patents

Abstract

PURPOSE:To obtain advantageously the titled compound useful as an intermediate for medicines, agricultural chemicals, etc., by reacting a trichloromethylbenzal chloride with hydrogen fluoride in the vapor phase in the presence of a catalyst containing aluminum fluoride in combination with a specific metal fluoride. CONSTITUTION:A trichloromethylbenzal chloride or a derivative thereof is reacted with hydrogen fluoride at 1:3-6, preferably 1:3.2-4.6 molar ratio between the former and the latter in the vapor phase in the presence of (A) aluminum fluoride and (B) at least one metal selected from zinc, chromium, manganese, iron and nickel, preferably iron at 180-400 deg.C, preferably 200-350 deg.C to give the titled compound useful also as an intermediate for dyes selectively at a sufficiently high reaction rate in high yield. The ratio of the component (B) to the component (A) is usually 0.2-20wt%, preferably 0.5-10wt%, and the component (B) needs to be finely dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing trifluoromethyl henzal chloride or its derivatives, and in particular to a method for producing trifluoromethyl henzal chloride or its derivatives by reacting trichloromethyl henzal chloride or its derivatives with hydrogen fluoride or the like. The present invention relates to a method for producing a derivative.

Trifluoromethylbenzal chloride or its derivatives are used as medicines, intermediates for dyes, and 1. It is useful. It has been reported that ortho-trifluoromethyl henzal chloride can be produced by reacting the corresponding trichloromethyl henzal chloride with hydrogen fluoride in a heterogeneous system in a liquid phase (Ana 1. Chem. , Acta,
10, P34.1954; J, Chem, Soc, 40
03.1960). In this case, the temperature is 90-150°C and the pressure is 70-14 (1 atm). However, in this method, the reaction rate is insufficient and a large excess of hydrogen fluoride is used to improve the yield. It is unsuitable as an industrial production method because it requires a long reaction time, the yield of the target product is low, and there are difficulties with the equipment due to the need to stir under high pressure. A). on the other hand,
For meta, para-trifluoromethylbenzal chloride or derivatives thereof, the corresponding meta-, para-trichloromethylbenzal chloride or derivatives thereof is reacted with 1
A method for producing PA by fluorination using hydrogen fluoride under a pressure of ~3 atm has been proposed (Japanese Patent Laid-Open No. 58-7
No. 9936). However, even with this production method, the yield is quite low and is not industrially satisfactory.

The present inventor conducted a study on the gas phase catalytic reaction of trichloromethylbenzal chloride or its derivatives with hydrogen fluoride near normal pressure in order to improve the various drawbacks of fF in the conventional method. By using a catalyst in which fluoride of a specified metal is combined with 1, the target trifluoromethyl henzal chloride or its derivatives can be selectively obtained in high yield, and the reaction rate is also sufficient. We have made two major discoveries and have completed the present invention. 11j In the present invention, trichloromethylbenzal chloride or a derivative thereof as a raw material has two active groups that can be fluorinated, a trichloromethyl group and a dichloromethyl group, but only the former trichloromethyl group is selectively fluorinated. A remarkable effect of fluorination on yield is exhibited. According to the present invention, aluminum fluoride and lead chloride,
In the presence of a fluoride of one or more metals selected from the group consisting of chromium, manganese, iron, and nickel, trichloromethylbenzal chloride or a derivative thereof and hydrogen fluoride are mixed in a gas phase. Provided is a method for producing trifluoromethylbenzal chloride or a derivative thereof, which is characterized in that the corresponding trifluoromethylbenzal chloride or a derivative thereof is obtained by reacting the compound under the above conditions.

Conventionally, for example, in JP-A-54-130524, trichloromethylbenzene or its derivatives are reacted with hydrogen fluoride in the presence of aluminum fluoride to purify the corresponding trifluoromethylbenzene or its derivatives. A manufacturing method is disclosed. However, when trichloromethylbenzal chloride or its derivatives, which are the raw materials of the present invention, are used, with known catalysts such as the above-mentioned aluminum fluoride, the fluorination reaction generally proceeds as a sequential reaction, resulting in by-products. It is difficult to selectively obtain trifluoromethylbenzal chloride or its derivatives in high yield.

Trichloromethylbenzal chloride or its derivative used as a starting material in the present invention is 〇-5m-1p
-) dichloromethylbenzal chloride or those in which hydrogen in the benzene ring is substituted with fluorine, chlorine, bromine, alkyl groups such as methyl groups, nitro groups, cyano groups, etc. Specific examples include 2-chloro-3 -Trichloromethylbenzal chloride, 2-chloro-4-trichloromethylbenzal chloride, 2-chloro-6-trichloromethylbenzal chloride, 2-chloro-5-trichloromethylbenzal chloride, 3-chloro-4-trichloro Methylbenzal chloride, 3-chloro-6-trichloromethylhensal chloride, 2-trichloromethyl-4-chlorobenzal chloride, 2-trichloromethyl-5-chlorobenzal chloride, :(-trichloromethyl-4-chloro Benzal chloride, :(-chloro-5-trichloromethylhenzal chloride, 2,4-dichloro-3-trichloromethylbenzal chloride, 2,5-dichloromethybenzal chloride, 2,4-dichloro-6-trichloro Methylhenzal chloride, 2,6-dichloro-3-trichloromethylbenzal chloride, 2-fluoro-3-trichloromethylbenzal chloride\2-fluoro-5-
Trichloromethylbenzal chloride, 2-fluoro-6
-Trichloromethylbenzal chloride, 3-trichloromethyl-4-fluorobenzal chloride, 3-fluoro-5-trichloromethylbenzal chloride, 2,5-difluoro-3-trichloromethylbenzal chloride, 2
-bromo-3-trichloromethylbenzal chloride, 2
-bromo-5-trichloromethylbenzal chloride, 2
-Bromo-6-trichloromethylhenzal chloride, 3
-bromo-5-trichloromethylbenzal chloride, 2
．． 5-dichloro-4-trichloromethylbenzal chloride, 2-fluoro-4-trichloromethylbenzal chloride, 2-trichloromethyl-5-fluorobenzal chloride, 3-fluoro-4-trichloromethylbenzal chloride, 2. 5-difluoro-3-trichloromethylbenzal chloride, 2-bromo-4-trichloromethylbenzal chloride, 3-bromo-4-trichloromethylbenzal chloride, 2-trichloromethyl-5-nitrobenzal chloride, 3- Examples include trichloromethyl-5-methylhensal chloride, 2-trichloromethyl-5-cyanobenzal chloride, and the like.

Among these, when 0-trichloromethylbenzal chloride or its derivatives are used as a raw material, the reaction targeted by the present invention can be carried out more selectively. As a derivative, a preferable effect can be obtained in the case of a substituted derivative of a halogen atom, especially a chlorine atom.

In the present invention, bent lead is used as a catalyst together with aluminum fluoride.
It is extremely important to use at least one fluoride selected from the group consisting of manganese, iron, and nickel, preferably iron fluoride. The reaction rate (conversion rate) of trichloromethylbenzalchloride or its derivatives, the ratio of trichloromethylbenzalchloride 1.71 or its derivatives (selectivity), which is a primary substance in the product, or both are extremely low. This results in a decrease in yield. The reason why the desired trifluoromethylbenzal chloride or its derivatives can be obtained with high conversion rate and selectivity by using the above-mentioned aluminum fluoride and the specified metal fluoride condensation catalyst of the present invention will be explained in detail. Although it is not known, the reaction to obtain the desired fluorinated product is a multi-step fluorination reaction, an intermolecular and/or intermolecular reaction of partially fluorinated functional groups (active groups) of the trichloromethyl group and dichloromethyl group. This is thought to be due to the fact that the specified metal fluoride catalytically contributes to the promotion of the pre-reaction, which consists of a pre-reaction with a heterogenization reaction.

The aluminum fluoride used in the present invention is not limited by crystal type or the like, and α-1β-1γ-aluminum fluoride or a mixture thereof can be used. Among these, α
Particularly preferred are molds. The fluorides of zinc, chromium, manganese, iron, and nickel used in the present invention include lead fluoride (7,n'F2) and chromium difluoride (CnFz), respectively.
,"": Chromium fluoride ((': r+ +'3), Yotsu-Sotokurois (Cn i"4), manganese fluoride (MnIi'z), manganese fluoride Mr+ F3), manganese tetrafluoride (M n F now)
, ferric fluoride (F' e F2), ferric fluoride (FeFj), -7-vito nickel (N i
+'2), nickel fluoride (Ni li゛))
etc., and hydrates of these compounds can also be used.

The ratio of 1 scale or 2 or more metals selected from the group consisting of iron, chromium, leek) 1 l, II++ lead, and manganese to aluminum fluoride is 1 no. The usual content is 0.2 to 20% by weight, and the content is 0.5 to 10% by weight, and must be finely dispersed. If the proportion of metal fluoride is out of the range specified by L, the conversion rate and selectivity of the reaction will be +1, indicating the effectiveness of the combination of two or more metal fluorides, which is a feature of the present invention. The best way to prepare such a catalyst according to the present invention is to disperse the above-mentioned metal salts in the form of an aqueous solution or by heating them inside the particles of porous aluminum fluoride. After absorption and heating in the form of a solution using a solvent other than water, such as an aqueous solution of the nitrate or chloride, the resulting metal salt-supported aluminum fluoride particles are optionally treated with nitrogen or chloride. Usually 500 q in a stream of hydrogen fluoride gas diluted with inert gas or air
This is a method of converting metal salts into metal fluorides by heating in a temperature range of up to .

In this case, it is not necessarily necessary to convert all metal salts such as chlorides other than the above-mentioned fluoride into fluorides, and it is also possible to use aluminum fluoride carrying the metal salts in the reaction. The metal salt can be converted into fluoride in order to achieve the intended purpose. At this time, the porosity of the aluminum fluoride 011 particles was 25.
~80% and the surface area measured by BE' method is 15 m
/g or more I"!tno<c: 30 m/g or more, and those with a pore diameter of 20 to 2000 A are preferably used,
The average particle size is 2 from 1fi for handling during reaction, etc.
0-l OOOBm preferably 50-500 It m
Preferably. The method for producing such aluminum fluoride particles is not particularly limited, and any known method may be used. To prepare Sen's catalyst, activated alumina having appropriate porosity, surface area, and particle size is supported with salts of other metals in the same manner as described above without being converted into aluminum fluoride in advance, and then A method in which both the activated alumina and the metal salt supported thereon are simultaneously fluorinated with hydrogen fluoride is also used.

The starting ratio of trichloromethylbenzal chloride or a derivative thereof and hydrogen fluoride, which is the starting point of the present invention, is preferably 3 to 6 moles per 1 mole of the former; 3.
It is necessary to control the amount of hydrogen fluoride to 2 to 4.8 moles, and the amount of hydrogen fluoride to be supplied is the above vI! When l+i4 is less than the limit, the conversion rate decreases, and when it is more than the 1-6 limit, the selectivity decreases rapidly. In the present invention, there is no problem in converting a gas such as nitrogen or argon or a low-boiling organic compound that does not participate in the reaction into the reaction system as a diluent.

In addition, the reaction temperature in the present invention is preferably 180 to 400°C. If the buckwheat temperature becomes too high, the selectivity of the reaction will decrease and the catalyst will deteriorate significantly. The reaction pressure is not particularly limited and can be carried out under increased pressure or reduced pressure, but it is usually carried out around normal pressure.

The space velocity when carrying out the present invention varies depending on the reaction temperature, catalyst activity, etc., but is 200 to 5000 hr.

Preferably it is 400 to 4000 hr'; if it is less than the lower limit of this range, the selectivity will decrease, and if it is greater than the upper limit, the conversion rate will decrease. In addition, when the activity of the catalyst decreases due to long-term use, the activity can be restored by using oxygen or air diluted with nitrogen or the like at a temperature of 350 to 500° C. as necessary.

In carrying out the method of the present invention, trichloromethylbenzal chloride or its derivative and hydrogen fluoride,
Depending on the situation, a diluent and a concentric mixture are introduced into a heated contact reaction tube and a predetermined reaction is carried out. In addition to a fixed catalyst bed, a fluidized bed or the like can be used for the reaction. Usually, these raw materials are heated and vaporized by passing them through a preheater before being supplied to the reaction tube. After the reaction, the hydrogen fluoride and hydrogen chloride that come out of the reaction tube along with the reaction products are easily separated based on the boiling point difference between them and the target compound. The resulting Wagyu acid product is purified using distillation, extraction, and other methods.

According to the present invention, the reaction can be carried out with extremely high conversion and selectivity, and as a result, in the case of ortho-trifluoride and I-methylhenzal chloride or its derivatives, 1
The molar ratio of the target product obtained at a boiling point of 5% or more, preferably at a yield of 90% or more under poor conditions (based on the feed rate),
In the case of meta- or para-trifluoromethylhenzachloride or its derivatives, it can be produced with a yield of 8% or more, or 85% or more under extreme conditions! do.

Example 1 ゜゛1'・Roll diameter 200mm. m,) mouth (person 1fI mouth 1° measured by the 1゛ method [i 0 n'i/ g,
Porosity: 4.5%, measured with a mercury porosimeter 1) Or an α-type fluoride with an average pore size of 25 OA? Take 50g of aluminum particles and separate 3 (10m
After placing the flasks in 1-liter flasks and evacuating them, 150 ml of the following solution was poured into each flask.

■ 20% (weight ratio) aqueous solution of Fe C13 ■ Cr
12% (weight ratio) aqueous solution of C'lz ■ N i CI
2:3% (weight ratio) aqueous solution■ Zn C12-12
% (weight ratio) aqueous solution ■ M n C: 23% (by weight) of I
After each solution was stirred for 2 hours under an aqueous solution (weight ratio), the aluminum fluoride particles impregnated with the metal chloride were filtered off. After heating and drying this at 130°C for 5 hours under reduced pressure, it was filled into a Monel tube with a diameter of 1/4 inch, and for those carrying Zn, CI2, and MrlClz: (30°C, 20 for Sen's
While maintaining the temperature at 0° C., hydrogen fluoride and nitrogen were each introduced at a flow rate of 200 ml/min for 4 hours to convert chloride supported on aluminum fluoride into fluoride. )
1 (The weight ratio of each metal fluoride to aluminum fluoride was calculated from the serious injury change as follows.

(1) Fe1i'J Fi,3? ai% (2)
Cr F2 2.9% by weight (3) N i FL Fi, 9% by weight 171)
7. nFz 2.7% by weight (5) Mnl-″λ5
．． 8% by weight It was confirmed by X-ray diffraction analysis that aluminum fluoride remained in the α-type at this point.

1-t in writing! 4 or (1) to (5) each using aluminum fluoride with a metal fluoride as a catalyst, the diameter;
(A 74-inch Monel reaction tube was filled.

Next, while maintaining the temperature of the reaction tube at 250°C, 0-trichloromethylbenzal chloride was added at a rate of 50 g/hr, and hydrogen fluoride and nitrogen were each added to 0-trichloromethylbenzal chloride (). They were introduced into the reaction tube at a ratio of 4 times and 7 times the molar amount (space velocity; approximately 900 hr').

After the reaction reached a steady state, nitrogen, hydrogen chloride, and excess hydrogen fluoride in the gas were separated using a condenser in which the HF gas was kept at zero for 5 hours to obtain a liquid component. Reduce this
Purification by centrifugation gave 0-trifluoromethylbenzal chloride. The product was confirmed by elemental analysis, gas chromatography analysis, IR spectrum, 13C-NMR spectrum, and GC-mass spectrum. The yield fl (g) and yield (%) of the product trifluoromethylbenzal chloride obtained for the metal fluoride-supported catalysts (1) to (5) in Section L are shown below.

(1) 189g (92%) (2) 175g (85%) (3) 179g (87%) (4) 177g (86%) (5) 174. g (85%) Example 2゜0-) p- instead of dichloromethylbenzalchloride
p-Trifluoromethylbenzal chloride was obtained in exactly the same manner as in Example 1 except that trichloromethylbenzal chloride was used.

Yield 4B (g) and yield (%) when using each catalyst
are not shown below for each of the metal fluoride scales (1) to (5) supported in the same manner as in Example 1.

Claims (1)

[Claims] 1) Trichloromethylbenzal chloride or a derivative thereof and hydrogen fluoride in the presence of aluminum fluoride and a fluoride of at least one metal selected from the group consisting of zinc, chromium, manganese, iron and nickel. A method for producing trifluoromethylbenzal chloride or its derivatives, which is characterized by reacting in a gas phase.